727 question

I have what appears to be a 79 727 truck tranny in my ratrod , the stamping is

4058324..........440..........727..........truck, short(W/O lockup)(rear timing)

Im going to put a shift kit in it , and was wondering what is rear timing , I found this on a site when I was chasing the stamping # down.

Thanks guys
Donnie

This means there is a site hole on top of the bell housing and the timing was done here instead of the front of the motor. Timing marks would be on the torque converter.

Thanks.
Mine does have a plastic plug on the top front of the tranny like the pic.
Donnie